A heatpump system (i.e., a refrigerant system) can be used to control the temperature of a certain medium such as, for example, the air inside of a building or automobile. A heatpump system generally comprises an evaporating heat exchanger (e.g., an evaporator), a compressor, a condensing heat exchanger (e.g., a condenser), a metering device (e.g., a metering/expansion valve), and a series of lines (e.g., pipes, tubes, ducts) connecting these components together so that refrigerant fluid can cycle therethrough.
In a heatpump system, refrigerant fluid enters the evaporating heat exchanger as a low pressure and low temperature vapor-liquid. As the vapor-liquid passes through the evaporator, it is boiled into a low pressure gas state. The fluid from the evaporator is drawn through the compressor, which increases the pressure and temperature of the gas. From the compressor, the high pressure and high temperature gas passes through the condensing heat exchanger whereat it is condensed to a liquid. The condensed liquid is then passed through the metering device whereat it is converted into the low pressure and low temperature vapor liquid for entry into the evaporator to complete the cycle.
An evaporating heat exchange typically comprises one or more flow passages through which refrigerant fluid travels from the inlet to the outlet of the evaporator. As the evaporator absorbs heat from the surrounding medium, refrigerant fluid within the flow passages evaporates. Ideally, an equal ratio of gas-to-liquid refrigerant will travel through each flow passage of an evaporating heat exchanger, as this yields a high heat transfer rate. A high heat transfer rate can translate into improved performance, greater efficiency, reduced power consumption, increased capacity and/or smaller package size.